Andrea Slachevsky Ch

Córtex prefrontal y trastornos del comportamiento: Modelos explicativos y métodos de evaluación

Los trastornos del cortex prefrontal (CPF) permiten explicar la sintomatologia de importantes cuadros neurologicos y psiquiatricos, tales como las secuelas de traumatismos encefalo-craneanos y las esquizofrenias. Sin embargo, y a pesar de la gran importancia de sus funciones, su estudio se ha visto dificultado por razones teoricas, experimentales y clinicas. Recientemente han surgido dos nuevos modelos que intentan explicar los mecanismos a la base del funcionamiento del CPF. Presentamos una revision de las principales manifestaciones clinicas ante su disfuncion, los modelos explicativos postulados tradicionalmente, ademas de las dos propuestas recientes de Koechlin y Mesulam, para finalizar con una revision de los instrumentos mas utilizados en el ambito clinico para la evaluacion de las funciones propias de esta region, denominadas funciones ejecutivas y de autorregulacion del comportamiento

Propiedades psicométricas y utilidad diagnóstica del Addenbrooke's Cognitive Examination-Revised (ACE-R) en una muestra de ancianos chilenos

BACKGROUND The Addenbrookes Cognitive Examination - Revised (ACE-R) is a good alternative to the Mini Mental State Examination (MMSE) for assessing cognitive capacities in dementia. AIM To estimate the psychometric properties and diagnostic utility of the Addenbrookes Cognitive Examination-Revised (ACE-R) in a Chilean elderly sample. MATERIAL AND METHODS ACE-R was adapted for the Chilean population (ACE-R-Ch) and then administered to 60 dementia patients, 22 mild cognitive impairment (MCI) patients and 45 control subjects in addition to the MMSE for assessing global cognitive efficiency. Caregivers of dementia patients and collateral sources of MCI patients and elderly subjects without dementia were interviewed with measures of dementia severity, functional status in activities of daily living and cognitive changes. Convergent validity, internal consistency reliability, cutoff points, sensitivity and specificity for ACE-R-Ch were estimated. RESULTS Regarding convergent validity, the ACE-R-Ch showed significant correlations (p < 0,001) with another cognitive measure (r = 0,952 with MMSE), a rating for dementia severity (Spearman rho=-0,822 with CDR), functional capacity assessments (r = -0,70 with ADLQ-Ch; r = -0,725 with PFAQ-Ch; and r = 0,650 with IADL Scale) and a measure of cognitive changes (r = -0,633 with AD8-Ch). In terms of reliability, the test had a Cronbach alpha coefficient of 0.918. The best cut-off point to distinguish cases of dementia from control subjects was a score of 76, which reached a sensitivity of 0.92 and a specificity of 0.93. CONCLUSIONS The ACE-R-Ch showed acceptable psychometric properties, becoming a valid and reliable instrument to assess global cognitive efficiency or cognitive impairment. Its diagnostic utility to detect dementia patients also worked very well in a Chilean elderly sample.

Enfermedad de Alzheimer: Actualización en terapia farmacológica

Dementia in general, especially Alzheimer disease and vasculardementia, are diseases of high prevalence with severe socio-economic consequences in allcountries. In recent years, due to the obtention of new pharmaceutical products acting ondifferent brain neurotransmitters, there has been important changes in the therapy of thesediseases. Although these drugs do not stop disease progression, there is consistent evidence of theirusefulness in cognitive, behavioral and functional domains and of their pharmaco-economicaljustification. This article reviews the main drugs available for Alzheimer disease and some futuretherapeutic perspectives (Rev Med Chil 2005; 133: 224-30).(

Modelos neurocognitivos en la esquizofrenia: Rol del córtex prefrontal

Introduccion: Los modelos neurocognitivos han dado lugar a un importante avance en la comprension de diversos desordenes mentales tales como la esquizofrenia (EQZ). En ese contexto, la disfuncion del cortex prefrontal (CPF) es un hallazgo central para explicar su sintomatologia. Se ha observado que los niveles anormales de activacion de la CPF, asi como disfunciones en la conectividad con otras estructuras cerebrales, juegan un importante rol en la delimitacion de la enfermedad. Material y Metodos: A traves de una revision teorica, empirica y clinica se describiran cinco aproximaciones neurocognitivas de la esquizofrenia. Conclusiones: Aunque la etiologia de la EQZ es probablemente multiple, un desorden de la interconectividad neuronal, y especialmente de la CPF explican un amplio espectro de su sintomatologia

Síntomas psicológicos y conductuales asociados a demencias: actualización terapéutica

Behavioral disturbances in dementias are relevant because they arevery common, they worsen patients’ medical and cognitive condition, increase the caregiverburden and accelerate the admission to nursing homes. The different behavioral disturbances indementias can appear isolated, but in most cases, patients present a combination of disturbancesproducing one of two main syndromes: the psychotic or the affective syndrome. Proper handlingof these behavioral disturbances requires a correct characterization of the syndrome, discardingmedical or environmental causes and selecting the drug with the better effectiveness and safetyprofile for each patient. In spite of the important number of psychotropics available, there is notenough scientific evidence about their real effectiveness and security in patients with Alzheimer’sdisease. This article reviews recent advances in the treatment of most common and disruptivebehavioral disturbances (Rev Med Chile 2005; 133: 1242-51).(

Percepción de conocimiento sobre las Demencias en Profesionales de la Salud de Chile

Sr. Editor El aumento de la esperanza de vida se ha asociado a un aumento exponencial de las personas con enfermedades cronicas no transmisibles, entre ellas la enfermedad de Alzheimer y otras demencias. En Chile, uno de los paises mas envejecidos de Latinoamerica, mas de 180 mil personas (1% de los chilenos) presenta algun tipo de demencia, cifra que se incrementara a mas de 626000 personas (3% de los chilenos) en 20501. Las demencias constituyen la enfermedad con el mayor incremento porcentual como causa de anos de vida perdidos por discapacidad o muerte prematura (mas de 200% en los ultimos anos) y como causa de muerte, con un incremento de mas de 526%.2, 3 No obstante lo anterior, estudios internacionales sugieren que el conocimiento que tienen los profesionales de la Salud respecto de estas patologias es insatisfactorio y no se condice con el impacto en la salud publica de estas enfermedades 4 . En Argentina5 , un estudio mostro que mas del 60% de los medicos consideraba no tener suficiente conocimiento en esta area, siendo esta situacion mas acentuada en los medicos generales. En Chile, los curriculum de las profesiones medicas aun abordan escasamente los trastornos demenciantes y no existen datos sobre el nivel de conocimiento de los profesionales de salud. Leer mas...

Cuidados paliativos en personas con demencia severa: reflexiones y desafíos

Dementia is an important public health problem due to the complex challenges it poses during the progression of the disease and especially during its end-of-life stage. The aim of this article is to consider the issues that arise from the use of commonly administered therapies in patients with severe dementia. Scenarios where excessive or futile therapeutic interventions might occur are discussed. The article concludes that it is advisable to analyze the clinical criteria and ethical considerations related to the administration of those treatments in order to develop and disseminate better practice guidelines for health professionals.Dementia is an important public health problem due to the complex challenges it poses during the progression of the disease and especially during its end-of-life stage. The aim of this article is to consider the issues that arise from the use of commonly administered therapies in patients with severe dementia. Scenarios where excessive or futile therapeutic interventions might occur are discussed. The article concludes that it is advisable to analyze the clinical criteria and ethical considerations related to the administration of those treatments in order to develop and disseminate better practice guidelines for health professionals.

Parálisis general sifilítica: presentación de 5 casos

We report five male patients, aged 35 to 63 years who suffered from paretic neurosyphilis. The clinical course was that of a subacute dementia with a frontal syndrome, with more apathy than euphoria. All were HIV negative and four were heterosexual. In all, the cerebrospinal fluid had a mononuclear pleocytosis and a positive VDRL. EEG was abnormal in the 3 cases in whom it was performed. One patient in whom a brain angiography was performed, had images of vasculitis. Treatment with 18-24 million units of penicillin per day during two weeks or more, was partially effective.We report five male patients, aged 35 to 63 years who suffered from paretic neurosyphilis. The clinical course was that of a subacute dementia with a frontal syndrome, with more apathy than euphoria. All were HIV negative and four were heterosexual. In all, the cerebrospinal fluid had a mononuclear pleocytosis and a positive VDRL. EEG was abnormal in the 3 cases in whom it was performed. One patient in whom a brain angiography was performed, had images of vasculitis. Treatment with 18-24 million units of penicillin per day during two weeks or more, was partially effective.

Descomponiendo el síndrome de déficit atencional en el adulto: hacia un entendimiento de su heterogeneidad pronóstica

Attention Deficit/Hyperactivity Disorder (ADHD) is a clinical syndrome characterized by an onset in early life. More than 65% of patients persist with manifestations of ADHD in adulthood. These symptoms may interfere in activities of daily-living, interpersonal relationships and professional and academic achievement. Nevertheless, the observation of an important group of adults with ADHD who do not show significant difficulties in the areas mentioned before puts into evidence the prognostic heterogeneity of this disorder. One of the current, most accepted explanations is the Double-Pathway Model: two double-dissociated deficits (Executive Disorders and Delayed-Reward Processing impairments) are involved in the genesis of ADHD, which explains the existence of different behavioral phenotypes. Moreover, personality traits like tenacity or perseverance are associated with higher levels of achievement in adults. On these grounds, we propose the hypothesis that the neurobiological correlate of tenacity/perseverance is a preserved Delayed-Reward Processing capacity, although further studies are needed to verify this idea.Attention Deficit/Hyperactivity Disorder (ADHD) is a clinical syndrome characterized by an onset in early life. More than 65% of patients persist with manifestations of ADHD in adulthood. These symptoms may interfere in activities of daily-living, interpersonal relationships and professional and academic achievement. Nevertheless, the observation of an important group of adults with ADHD who do not show significant difficulties in the areas mentioned before puts into evidence the prognostic heterogeneity of this disorder. One of the current, most accepted explanations is the Double-Pathway Model: two double-dissociated deficits (Executive Disorders and Delayed-Reward Processing impairments) are involved in the genesis of ADHD, which explains the existence of different behavioral phenotypes. Moreover, personality traits like tenacity or perseverance are associated with higher levels of achievement in adults. On these grounds, we propose the hypothesis that the neurobiological correlate of tenacity/perseverance is a preserved Delayed-Reward Processing capacity, although further studies are needed to verify this idea.